what will plugging the wastegate hose do with a stock exhaust????

[GMC-2002-Dmax]

Hey everyone,

I have had my gauges in for a week or so and I am "juiced" with v3.61. Anyway I have read posts about boost pressure and have seen am max of 25 psi so far. I also have a K&N filter and stock exhaust. EGT's are being read at about 1" off the pass manifold in the exhaust downpipe and I have a baseline temp. established.( I add 200 degrees for distance from turbo ).

My question is will altering the wastegate or disconnecting it do anything to harm the DMax?? Can I get more boost than 25 psi, and do I need more???

Will I get more boost with a JK 4" exhaust to 5" pipe or will 4" get me by ?? Or will a muffler change be good enough???

HELP ME OUT GUYS, and GALS !!!!

Thanks,

GMC :D

[ 08-01-2002: Message edited by: GMC-2002-Dmax ]</p>

[SoCalDMAX]

OK, here's what I found, but others may have different results.

I disconnected the wastegate and plugged the line. With propane and the Power Plug on, I saw up to 31psi of boost. It did not feel any faster, nor did it sound good. It started detonating up in the 30psi range at high rpm. I only did this for a short while and it is connected now.

EGTs may have been slightly lower, but not enough to tolerate the detonation. I'm *guessing* that the MAP sensor was detecting too high of boost readings and defueling to drop the boost levels. That's what it felt like. I'm not sure at what level it occurs (maybe 27 to 29psi?) or even if it's true.

Conclusion: I wouldn't just plug it off. If you want to experiment, do a bleeder, like an aquarium valve. A 4" exhaust will definitley help, and you may see a DECREASE in boost, since it will flow more air and boost is actually intake backpressure. I think the real numbers to watch are EGTs at specific boost level/RPM/load.

A 4" exhaust will help, full 5" is overkill and too loud, JK's hybrid 4"/5" should be really nice and a muffler alone probably won't do much.

Remember, this is JMHO, no dyno testing to back any of it up.

Regards, Steve